If my projected Social Security benefit is larger than the maximum monthly benefit, can I still take advantage of delayed retirement credits?

Yes. The maximum benefit is for those who have reached full retirement age (FRA). If your projected monthly benefit is $2,663 (the maximum monthly benefit for someone reaching FRA in 2015), you can still take advantage of delayed retirement credits between the year you reach FRA until you reach age 70. So, you would technically receive more than the maximum amount.